Polymeric nanoparticles have attracted increased attention over the past several years in a variety of fields, including catalysis, combinatorial chemistry, protein supports, magnets, and photonics. Similarly, vinyl aromatic (e.g., polystyrene) microparticles have been prepared for various uses, such as, for example, as a reference standard in the calibration of various instruments, medical research, and medical diagnostic testing. Although it is known that the addition of polymeric nanoparticles to rubber compositions can improve various characteristics of a rubber composition, indiscriminate addition of polymeric nanoparticles to a rubber matrix can also cause degradation of the matrix material. Accordingly, advances are needed in the art of improving the characteristics of rubber compositions via the addition of polymeric nanoparticles.
A polymeric nanoparticle includes a core being at least partially crosslinked, a plurality of first shell block polymer arms and a plurality of second shell block polymer arms, each arm being attached to the core. The monomer residues of the first shell block polymer arms are different than monomer residues of the second shell block polymer arms.
A rubber composition includes a rubber matrix; at least one filler, and nanoparticles. The nanoparticles include a core that is at least partially crosslinked, a plurality of first shell block polymer arms, and a plurality of second shell block polymer arms, each arm being attached to the core. The monomer residues of the first shell block polymer arms are different than monomer residues of the second shell block polymer arms.
A process for preparing multi-armed nanoparticles includes the steps of: (a) polymerizing a first shell block monomer into a plurality of first shell block polymer arms; (b) polymerizing a second shell block monomer into a plurality of second shell block polymer arms; and (c) combining the first shell block polymer arms and the second shell block polymer arms with a core monomer and polymerizing the core monomer onto the first shell block polymer arms and the second shell block polymer arms. The monomer residues of the first shell block polymer arms are different than monomer residues of the second shell block polymer arms
A polymeric nanoparticle includes a core being at least partially crosslinked, a plurality of first shell block polymer arms, and a plurality of second shell block polymer arms, each arm being attached to the core. The first shell block polymer arms each comprise at least one monomer residue having at least one polar moiety with a dipole moment of at least 0.5 D.
A living anionic polymerization process for preparing Janus nanoparticles, includes the steps of: (a) polymerizing a first shell block monomer into a plurality of first shell block polymer arms; (b) polymerizing at least one core monomer onto said first shell block polymer arms; (c) cross-linking the core monomer residues; (d) polymerizing a second shell block monomer onto said core block polymer to form a plurality of second shell block polymer arms; and (e) allowing at least partial phase separation between said first and second shell block polymer arms, thereby forming said Janus nanoparticles.
A polymeric nanoparticle includes: a core that is at least partially crosslinked, a plurality of first shell block polymer arms, and a plurality of second shell block polymer arms, each arm being attached to the core. The monomer residues of the first shell block polymer arms are different than monomer residues of the second shell block polymer arms. The first shell block polymer arms comprise a styrene moiety substituted with a heteroatomic group.